Combined seat and backrest unit for a chair

ABSTRACT

CLAIM 
     The ornamental design for a combined seat and backrest unit for a chair, substantially as shown and described. 
     DESCRIPTION 
     FIG. 1 is a front perspective view from above of the chair embodying our new design; 
     FIG. 2 is a rear perspective view from below of the chair; 
     FIG. 3 is a front view of the chair; 
     FIG. 4 is a rear view of the chair; 
     FIG. 5 is a plan view of the chair; and 
     FIG. 6 is a side view of the chair. 
      The broken lines disclosing a chair base in FIGS. 1-3 are shown for illustrative purposes only.



